I have to list favorites by type because there's so many I love but before i do
this. So much. Rolf may not be my favorite character. His demeanor is too bland and unrealistic for a kid, and w/o going through his support conversations he'd be entirely unmemorable. But he's written with a level of thoughtfulness many child characters in FE aren't, and his support/info convos are so unexpectedly philosophical and genuinely interesting that I can't help but appreciate his existence.
Come to think of it, this is pretty accurate to the entire cast of the Tellius series - not my favorite character, but i appreciate certain support/info convos that show how much thought went into developing said characters. Like Jill. I love that the narrative bothers to continually revisit her arc and show her progression of mentality, that in itself is moving to say nothing of her actual story. But I still wouldn't say she's one of my favorite characters.
On the other hand Nephenee was always one of my faves growing up, primarily because I really liked how she looked (I was a deep kid). But her character offers nothing too special (still very likeable of course, tho I'm not a fan of how exaggerated the 'country bumpkin' aspect had to be in RD iirc).
At any rate, lists. Ike, Ilyana, Tibarn, Sanaki, Janaff, Soren, Titania, Tormod and Haar are all up there for me. Nephenee, Sothe, Titania, Volke, Ulki and Ena all have some of my favorite designs.
Points to Fiona for "could've been my fave and had a ton of potential if she didn't disappear immediately after she stopped being relevant"
tbh it'd be easier to pick characters i don't like. i love everyone in tellius too much ;-;